An origin of 1/f fluctuations at a nonequilibrium phase transition

We present the results of experimental study of an intensive source of wide-band 1/f noise whose generation appears in a system of two interacting nonequilibrium phase transitions. Such a process has been realized in the region of superposition of a superconductor–normal conductor phase transition on a liquid–vapor crisis transition in a boiling cooler. A mathematical model describing phase transitions in a dynamical system with two interacting order parameters, converting “white” noise into two stationary stochastic processes with 1/f and 1/f2 spectra has been suggested. The properties of model oscillations with 1/f spectrum are qualitatively adequate to those observed in experiment. The characteristic difference of model oscillations with a 1/f2 spectrum from classic random walks has also been noted.